DESCRIPTION (Adapted from applicant's description): In this project the +___________ investigators will use spontaneous speech data and data from comprehension, imitation and judgment experiments to study the acquisition of Turkish as a first language by children between 1.5 and 6 years of age. These data will be used to address the following fundamental questions about language acquisition: 1. At what age do children begin to use functional category morphemes? 2. How productive is their early use of these morphemes? 3. Are young children predisposed to assume that the language they are acquiring has a fixed word order? 4. How do children learn to map words onto grammatical functions (e.g., subject, object)? 5. How do children learn to map these grammatical functions onto thematic roles? 6. Are young children predisposed to assume that grammatical particles are attached in a fixed order?